Any reason NOT to charge to 100% on a leased LEAF?

[GaslessInSeattle]

first off, not all battery packs are created equal in the Leaf. It's best, IMHO, to conserve what you have, since in actuality it seems to be a bit of a lottery system as to how much you start out with and how long it lasts. it's hard to tell how much of a difference charging to 80% vs 100% makes. the over arching influence appears to be ambient temps regardless of charging habits. that said, if you will be needing 100% of the capacity of the battery periodically throughout your Lease, it's best to stay on the safe side and be kind to your battery. for instance, quite frequently we need the Leaf for a run to the airport where it sits for days. we need to be able to do that round trip even in the winter and return to a cold soaked battery for the trip home, returning with a little bit in reserve for peace of mind. there is not much wiggle room in the winter even in a brand new battery for this trip, so we keep the car closer to 50% when more is not needed with the hopes of keeping it in top shape. we don't know how much we gain by doing this.

we charge to 80% or 100% whenever that is needed and we try and do that right before we use it, partly to warm the battery, partly to reduce the time it sits at a high SOC. the iphone app is handy for overriding the charging timer and charging to 100% by simply pressing charge now, it's the same as hitting the timer override button in the car. If you don't come even close to using up the full range in cold whether, then it probably doesn't matter how you charge.

read the manual on how to set the charging timer, it's a little tricky and very easy to not actually set it. get familiar with it, it takes a few times to learn it's ins and outs. there are a couple ways of using it. you can set it so that it always starts charging to 80 or 100% when plugged in by having it set for nearly 24/7, like 8am to 7:50 am. you can set it so that it never charges, but is plugged in so that you can have total control of charge timing through a phone app, by setting the charging time to say, 8am to 8:01 am. the other way is to choose a specific time window, typically at night, typically finishing close to when you are using it, especially if charging to 100%.

If you ever really need to stretch your range for a once in a while trip in the winter, there are a few ways to warm the battery a bit. at these times it's especially helpful to leave the battery at a lowish SOC then charge it up to finish an 80% charge about two hours before you need to leave, this warms the battery a bit initially. then initiate the climate control from the phone app and allow the car to warm up and charge at the same time. the warming and charging at the same time raises the temperature of the mass of the car, including the batteries somewhat. The next important thing is to drive a bit slower for these trips, keeping the energy use between 2 and 3 bubbles if possible, requiring slowing way down going up hills, with climate control turned off and mode set to foot defog, avoiding climate control use for as long as possible. periodically heating the car up and opening up the doors to release the moist air helps to dry the car out and reduce fogging... the power defrost and heater eat range if not done while plugged in and parked. liberally use the steering wheel and seat heaters, they are your best friend for staying comfortable when you need to extend range when you are cold (the most efficient transfer of heat to you). I can get 85 miles out of the Leaf, including hills, even in the winter here by doing the above.

 

[Deleted member 3147]

I charge to 80% about every other day, I dont know about other people's reasons, but the batteries are rated on charge cycles right? Maybe its not a common metric, but i've seen a table or list somewhere comparing charge cycles until battery replacement. Either way, I have a 20 mile round trip commute mostly 55+ and by the end of the 2nd day its low enough that I'm not sure I could make it a 3ed day. I average 4.5-4.6 Mi/kwh, so you would think I could easily get 3 days in on an 80% charge. :/

The thing is, when they talk about "charge cycles", they're talking about full charge cycles, e. g. 0 to 100%, or as close to that as you can get.

AFAIK, partial charge cycles are much gentler. a 50% cycle (e. g. 30% to 80%) actually counts as less than half of a full charge cycle. One of the best things you can do for your battery is a lot of small charges instead of fewer large charges.

 

[pennan]

In addition to the time at full charge, I thought that discharge to a low SOC is also damaging to the life of the batteries? I charge to 100% about 30 minutes before leaving each weekday morning on a 45 mile round trip commute. I thought that this minimizes time at 100% charge while also giving me more range if I need to do something besides just go to and from work, and also prevents me from regularly going very low. Can anyone comment on how low a SOC is concerning and whether it is better to minimize low SOC or time at 100% SOC?
(This question may soon become moot since my work is installing level 1 chargers and I would then I think just charge to 80% at home and 80% again at work.)

 

[GaslessInSeattle]

...
(This question may soon become moot since my work is installing level 1 chargers and I would then I think just charge to 80% at home and 80% again at work.)

definitely the way to go! there are no decent numbers comparing low soc to high soc. I believe low soc is bad mainly if you work a battery hard while it is low, since it has an increased level of internal resistance and is prone more to overheating... it's also more vulnerable, if left for long periods, to dropping critically low where the cells can't "wake up", hence the term "bricking" with the roadster. high state of charge leads to cladding of cathode and anode. neither high nor low is ideal, neither is probably that bad on occasion. somewhere in the 30-60% SOC is the absolute nicest for resting. shallow cycling mid pack is the best. unfortunately we have no numbers on how much of a difference these efforts will make. it appears that high ambient temps by far outweigh any other effect on aging.

 

[planet4ever]

In addition to the time at full charge, I thought that discharge to a low SOC is also damaging to the life of the batteries? I charge to 100% about 30 minutes before leaving each weekday morning on a 45 mile round trip commute. I thought that this minimizes time at 100% charge while also giving me more range if I need to do something besides just go to and from work, and also prevents me from regularly going very low. Can anyone comment on how low a SOC is concerning and whether it is better to minimize low SOC or time at 100% SOC?

Phil (Ingineer) tells us that "80%" is really 80% of total capacity, and that it is closer to 85% of usable capacity. I don't know what you think "low" is, but if you are charging to 100% for a 45 mile trip my guess is that you may be treating three bars as low. Well, guess what: When you drop to 3 bars you still have about 35% of the usable capacity of the battery left. So by charging to 100% I am guessing that you are living on about 2/3 of the battery capacity, but pushing the high end way harder than bottom end.

As far as I am concerned, "low" is when I drop below about 15% of available capacity, to match the 15% at the top I am avoiding by charging to "80%". And wouldn't you know it, that is about the time that the car gives me it's first "Your battery is low" announcement. By running 15% to 85% of usable capacity I'm using a bit more than 2/3, and not stressing either end.

I hasten to add that I don't always wait for Low Battery before charging; just that it doesn't worry me when it happens. If I get home with 5 bars or less I always charge. If I have 6 bars I know I still have more than half a "tank" (5 bars is half, not 6), and I don't charge unless I know I will be driving farther than usual the next day.

Ray

 

[TEG]

Please don't charge to 100% on DC QC unless you absolutely need it.

The last few % goes really slowly, and others can be waiting to use the charging station.

In particular, with Blink QC, the 2nd port doesn't activate until the other port is done charging.
Recently I have been finding myself "in the queue" more and more with people waiting for their 100% QC to finish.
I try to get them to stop early by saying "going all the way to 100% is slow and may be harmful to the battery", and the typical response has been "the car is leased, so I don't care..."